sustainability Article Optimal Consumer Electronics Product Take-Back Time with Consideration of Consumer Value Yi-Tse Fang and Hsin Rau * Department of Industrial and Systems Engineering, Chung Yuan Christian University, Taoyuan City 32023, Taiwan; [email protected] * Correspondence: [email protected]; Tel.: +886-3-265-4417 Academic Editor: Bhavik Bakshi Received: 21 September 2016; Accepted: 2 March 2017; Published: 7 March 2017 Abstract: Rapid economic growth in recent years has transformed our lifestyle to massively produce, consume, and dispose of products, especially for consumer electronics. This change has put great threat to our environment and caused natural resource depletion. Moreover, short product life cycles and quick replacements of consumer electronics create enormous electronic wastes (e-wastes). Without proper waste management, immense environmental damage is expected. In this empirical study, we notice that lots of valuable materials that can still be recycled from these used consumer electronics are left unused at home instead of being recycled at the appropriate time, which causes a low collection rate and a decrease in residual value for the used products. Therefore, it is important for the government and the recyclers to handle them efficiently by increasing the used product take-back rate. Our study develops an assessment model for customer value based on the idea of value engineering and the perspective of product life cycle. We also explore the relationship between product value and the total cost of ownership with an evaluation of their time variation, considering different usage modes for various consumer groups and different recycling award schemes (fixed and variable recycling awards). Proper take-back management is likely to create a win-win situation both for consumers and environmental protection. This study regards the notebook computer as an example to determine the optimal time for recycling laptops based on usage patterns and provides consumers a reference for when to replace their used product. The results from our modeling firstly clearly indicate that consumers with higher frequency of usage have shorter take back times and higher maximum consumer value. Secondly, a variable recycling award scheme with higher maximum consumer value is more practical than a fixed recycling award scheme. Keywords: product take-back time; consumer value; total cost of ownership; recycling award 1. Introduction The rapid development of technology has brought consumer electronics into our daily life in the past decades. This has changed the way we communicate, entertain, and obtain information. Innovative technology continuously pushes out the old model and brings in the new one to meet consumer’s demands. This has shortened the life cycle of consumer electronics and resulted in greater replacement and disposal compared to other products. Without proper recycling processes, these accumulated electronic wastes (e-waste) will not only pose threats to the ecological environment but also cause valuable resources to be destroyed or unused. According to the research of Balde et al. [1], the estimated amount of e-waste generated in 2014 was 41.8 million metric tonnes (Mt), and this was forecasted to increase to 50 Mt of e-waste in 2018. In Europe [2], e-waste is increasing at an annual rate of 3% to 5%, which is almost three times faster than the total waste stream. Developed countries are not the only ones that generate e-waste; developing countries are also expected to triple their e-waste production. United Nations Environment Program (UNEP) [3] estimated that 50 million tons of Sustainability 2017, 9, 385; doi:10.3390/su9030385 www.mdpi.com/journal/sustainability Sustainability 2017, 9, 385 2 of 17 e-wastes are produced each year globally, but only 15%–30% of e-waste is recycled; the rest go directly to landfills and incinerators. In addition, US government researchers [4] investigated the quantity of electronic products ready for end-of-life between 1990 and 2010; the result implies that 5 million short tons of electronic products are in storage, remain stockpiled, and are waiting for disposal. Today’s computer industry innovates at a rapid pace and brings new technologies with upgrades to market on average of every 18 months. According to data provided by the Statist a website [5], the average life of PCs and tablets is expected to drop in the next four years. While the average life for these devices was almost 3.1 years in 2013, that number is expected to drop to a little over 2.8 years by 2017. It shows that computer replacement has increased and caused a huge disposal problem. Kwak et al. [6] presented the results of an analysis of data collected from an e-waste collection center in Chicago, showing that the mean age of collected laptop computers is 11 years old, which is very different from its typical wear-out lifespan. United States Environmental Protection Agency (U.S. EPA) [7] discovered that many consumers did not recycle their consumer electronic products when they first became defunct or obsolete and more than 70% of retired products were kept in storage, typically for as many as 3–5 years. In order to resolve these serious waste problems caused by consumer electronics, the European Union proposed an Integrated Product Policy (IPP) [8] that aims to take a life cycle perspective instead of the end-of-pipe treatment. Integrated environmental awareness is blended into the processes from design, extraction of natural resources, manufacturing, assembly, distribution, and use to the eventual disposal as waste to reduce damage and pressure on the environment. It also needs to include all relevant stakeholder viewpoints for the whole product development process from idea generation to product management and reverse logistics. End-of-life management (EOLM) has become an important global issue in electronic consumer products, home appliances, and industrial equipment products recently. Many enterprises have successfully applied this management method as a feasible solution to solve the E-waste problem. Ramani et al. [9] define EOLM as the process of converting end-of-life products into remarkable products, components, or materials. It enables manufacturers to comply with environmental legislation while gaining economic advantages. EOLM can be divided into two parts: (1) product take-back, which is the process of acquainting the end of life products from the consumer; and (2) EOL recovery options, which take the products after the acquisition to elect product reuse, component reuse, and material recovery options [10–12]. Guide et al. [13] considered the uncertainty of quality and quantity, as well as the timing of end-of-life products that made EOLM difficult. In line with that dilemma, Rayet al. [14] proposed the concept of an active product recovery system. They believe that, through economic incentives, there is an opportunity to enhance consumer product recycling to achieve an economy of scale. While others addressed the issue as a problem of scheduling take-back, a problem in the demand for parts or recovered products with the objective to fulfill the demand at a minimum cost. White et al. [15] presented an overview of the EOLM problems existing in each stage of the product recovery process and showed that better information about product design, product quality, and timing can improve the product EOL opportunities. Zhao et al. [16] developed a model to help the manufacturers determine optimal take-back time and the number of lifecycles for warranty purposes. In addition, some literature explored recycling facility locations and the number of resource allocations for the optimal recycling solutions [17–19]. As summarized above, most of the product manufacturers (recyclers) explore an end of life product recycling strategy, with the goal either to identify product recovery process to obtain maximum profits at minimum cost or to reduce the impact on the environment. Conversely, only a few papers considered the value of the consumer, but none uses consumer value to study take-back time for consumer electronics, based on our best knowledge. This motivates our study. However, if we want to reduce the environmental impacts throughout the life cycle of a product, all the different actors and stakeholders, such as designers, manufacturers, consumers, and recyclers, should participate. In this study, in order to help consumers understand the perfect timing for the take-back of a laptop computer, Sustainability 2017 9 Sustainability 2017,, 9,, 385385 3 of 17 of a laptop computer, we have developed an assessment model from the consumer’s position and we have developed an assessment model from the consumer’s position and taken the point of view taken the point of view of a product life cycle to construct the consumer value over time. We have of a product life cycle to construct the consumer value over time. We have also considered the usage also considered the usage patterns of various consumer groups to obtain their different optimal take- patterns of various consumer groups to obtain their different optimal take-back times and to provide back times and to provide different consumers with a reference for their product replacement. different consumers with a reference for their product replacement. This paper is organized as follows. In addition to this introduction, Section 2 develops a This paper is organized as follows. In addition to this introduction, Section2 develops a proposed proposed assessment model. Section 3 illustrates the proposed assessment model using real data on assessment model. Section3 illustrates the proposed assessment model using real data on laptop laptop computers. Finally, Section 4 gives a conclusion with suggestions for future research. computers. Finally, Section4 gives a conclusion with suggestions for future research. 2. Model Development Value engineeringengineering (VE) is a powerful technique to determine the best relationshiprelationship between cost and value by analyzing product and process performance. It could be introduced at any point in the life-cycle ofof products,products, systems,systems, or or procedures procedures [ 20[20].].